Senior Backend Engineer - C# / Python

🔥 Senior Backend Engineer | AI x FinTech | London | £80k + Equity + Unlimited Holiday Oliver Bernard have recently partnered with a fast-moving AI fintech start-up that’s building an AI-native product from the ground up. They’re now looking for a Senior Backend Engineer to join their early engineering team. This is an opportunity to get in early, work directly with the founders and take real ownership of the technology. What you’ll own 👇 ⚙️ Design, build and own core backend services, APIs and infrastructure 🔄 Build event-driven, multi-tenant systems 🤖 Take LLM and agentic workflows from concept into production 🗄️ Own data models, failure modes, auditability and performance 🚀 Take features from spec → architecture → production 🔌 Build API-first systems and infrastructure 🧑 💻 Jump into React / Frontend when needed to get a feature shipped 🤝 Work directly with the founders and help shape the technical roadmap What they're looking for 3–4+ years shipping and owning backend systemsStrong C# / Python experienceExperience with AI tooling, LLMs or agentic workflowsFintech experience is essential — payments, banking, open finance, ledgers or financial infrastructure particularly relevantComfortable operating across the stack when neededSomeone who thrives in high-agency, fast-paced environments Why join? 🚀 This is an early team hire, so you'll have a level of ownership and influence that's difficult to find in a larger organisation. You’ll be close to the founders, have a direct impact on the product and get the chance to work at the intersection of AI + financial technology. 📍 London, 3–4 days in office 💰 Up to £80k + meaningful equity 🏖️ Unlimited holiday 🤖 AI-native product ⚡ Early-stage team / high agency / fast-paced If you're interested in getting in early at an AI-first fintech and want genuine ownership over what you build, Apply for more details. #Hiring #FinTech #AI #BackendEngineer #SoftwareEngineering #LondonTech #Python #CSharp #LLM #ArtificialIntelligence #Startups #TechJobs